from datetime import datetime
from hashlib import md5

from werkzeug.security import generate_password_hash,check_password_hash
from app import db
from flask_login import UserMixin
from app import login

@login.user_loader
def load_user(id):
    return User.query.get(int(id))

class User(UserMixin,db.Model):
    id=db.Column(db.Integer,primary_key=True)
    username=db.Column(db.String(64),index=True,unique=True)
    email=db.Column(db.String(120),index=True,unique=True)
    password_hash=db.Column(db.String(128))
    posts=db.relationship('Post',backref='author',lazy='dynamic')
    about_me=db.Column(db.String(140))
    last_seen=db.Column(db.DateTime,default=datetime.utcnow)


    def avatar(self,size):
        digest=md5(self.email.lower().encode('utf-8')).hexdigest()
        return 'https://www.gravatar.com/avatar/{}?d=identicon&s={}'.format(digest,size)

    def set_password(self,password):
        self.password_hash=generate_password_hash(password)
    def check_password(self,password):
        return check_password_hash(self.password_hash,password)
    def __repr__(self):
        return '<User {}>'.format(self.username)
class Post(db.Model):
    id=db.Column(db.Integer,primary_key=True)
    body=db.Column(db.String(140))
    timestamp=db.Column(db.DateTime,index=True,default=datetime.utcnow)
    user_id=db.Column(db.Integer,db.ForeignKey('user.id'))
    def __repr__(self):
        return '<Post {}'.format(self.body)

